Apparatus for brazing



1951 F. w. SCHWINN 2,579,997

APPARATUS FOR BRAZING File d June 11, 1948 Q I INVENTOR.

16 4222.? W Ja/z'wa'zzzz WQWZ- M Patented Dec. 18, 1.951

Es PATENT OFFICE APPARATUS FOR BRAZING Frank W. Schwinn, Chicago, 111.

I Application June 11, 1948, Serial No. 32,500

This invention relates to a method and apparatus for brazing which have particular application to the brazing of joints between parts having surface contours such that the normal area or having non-complementarily curved external contours.

My invention also has Within its purview the provision of a method and apparatus of the class referred to and by which the brazing metal is held in place with respect to the joint surfaces preparatory to, and during the brazing operation.

Considered structurally, the invention compre hends the provision of a metallic insert with surface portions shaped to fit adjacent parts of the members which are to be joined, so that the brazed joints are enlarged and strengthened by. their being established between said members and the fitting surface portions of the insert. I

In complement to the proceeding structura provision of the invention, I have further com-' prehended that for certain adaptationsthe said insert may be made in a form to grip at least one of the members, so as to assist in the retention of the parts in their assembled relationship during the brazing.

In further correlation to the preceding structural objects, my invention also has within its purview the provision of pieces of brazing metal formed to be retained in position relative to the joint surfaces until the brazing is accomplished.

Considered in respect to a specific adaptation, this invention provides a method and apparatus for effecting a strong and secure brazed joint between the side surfaces of a plurality Of bicycle frame tubes.

My method includes the step of inserting a steel insert which is contoured for fitting, asby coining, between the surfaces of the parts which are to be brazed.

Other objects and advantages of the invention will-he apparent from the following description and the accompanying drawings in which similar characters of reference indicate similar parts throughout the several views. l

2 Claims. (Cl. 28'754) Referring to the one sheet of drawings:

Fig. 1 is a side elevational view of a bicycle frame of a type embodying a joint to which a preferred form of my method and apparatus are well adapted and which adaptation serves as an exemplary disclosure of this invention;

Fig. 2 is a fragmentary side elevation view of a portion of the frame structure shown in Fig. 1, drawn to a considerably larger scale, better to illustrate the portion of the bicycle frame strucin the direction indicated by the accompanying arrows;

Fig. 4 is a fragmentary sectional view wherein the section is taken substantially on a line 44 of Fig. 2 and viewed as indicated by the arrows; and I Fig. 5 is an exploded perspective view of parts utilized in the joint of Figs. 1 to 4 inclusive and which, when utilized, follow a preferred adaptation of my disclosed method.

Although there are many adaptations in which brazed joints might well be utilized for'securing together non-conforming or non-complementa rily curved surfaces of metal parts and both my method and apparatus may be suited by variations to such uses, I have selected for illustrative and exemplary purposes a cluster joint between tubes of a bicycle frame structure.

. Having reference to Fig. 1, the illustrative. frame therein depicted includes a seat post mast l0 secured to and extending upwardly from a crank-hanger I2 and having at its upper end a seat post clamp l3. Secured to and extending forwardly from the upper portion of the seat post mast I0 and in substantially coplanar relationship therewith is an upper reach tube l4, one end of which is disposed in substantially abutting relationship to one side surface of the seat post mast. At its other end, the upper reach tube I4 is secured to a steering head l5. A lower reach tube l6 extends between and has its oppo-' site ends secured to the crank hanger l2 and the steering head l5. Extending from the crank hanger I2 in a direction substantiall opposed to the lower reach tube It is a rear fork l1.

As'depicted in Figs; 1 to 4 inclusive, substantially coextensive and parallel side tubes l8 and I 9 are disposed on and across opposite sides of the joint between the seat post mast In and upper reach tube l4. The'opposite end portions of the said tubes I8 and l9 are curved to provide upper stays 20 for the rear fork and forward braces 22. At their ends, the upper stays 20 are secured to the ends of the rear fork ll. At their other ends, the forward braces are secured to opposite sides of the lower reach tube I6.

For rigidifying the frame structure, it is desirable to provide a strong and durable joint for securing each of the side tubes l8 and 19 to the adjacent side surfaces of the upper reach tube I4 and seat postfmast -ll). In this instance as is often' the case, the adjacent surfaces of the parts between which the joints are desired are non-complementarily curved, so that their normal areas of surface contact are extremelygsmalls. For effecting the formation of rugged brazed joints, contacting surface areas fapprecia'b1e'- size desirable. brazed joints by methods such as that of using high frequency induction, apparatus for produc==- ing the heat for the brazing, it is preferable that the parts erribodied in the joint shall'iholdtogeth'enwhilethe heating is effected. V

For the 'purpose of obtaining rugged: brazed jointshaving-substantial surface areasabetween' the'opposed surfaces of each of the seat'rpost mast and upperreach tubes and thesurfacesof the side tubes *I8 'and'l9; I have provided a metal insert- 23, preferably of coined steel, which, in the -presentinstance, is made in thefornmofa clip having side portion 24 and 25 which fit b'e.-'-. tween the adjacenttubesurfaces and an integral connecting portion 26- which connects-the side portions and-aids in holding the insert in place duringthe-brazingoperationr As shown'inFi'g. 5} the-c1ip-type metal insert for the disclosed joint structure has surfaces shaped to conform to the adjacent tube members-so as to provide substantial surfaceareas-of contact, whereby each tube is strongly secured by brazing to an adjacent and conforming surface of the insert.

Concavely curved outer side surfaces Z'IJand 28of the-si'deportions 24 and 25 are shaped to conform to theadjacent inner surfaces of'the side tubes l8 and IS respectively. Internally-of the'clip-typeinsert, a partially cylindrical "surface =29- is formed at one end of the insert 'b'y portions of the'innersurfaces of the-side portions ZI-and- 25 and the inner surface of the connecting portion 25. This partiallycylindrical surface,

in-the=present instance, fits against'and conr for-ms to the surfaceof the=upper reach tube-14- adjacent the seat'post mast H]. Extended ends of the'side-pcrtions 24 and 25 provide-inner concavesurfaces 33 and 32'respectively which confor-m'to the-outer side surfaces of the seat post mast It; For extending the gripping surface which embraces the' upper reach tube -14, it 'is my preference to provide integrally formed'and projecting lugged portions 33 and'34 in" opposed relationship on the side portions 24' and-25re spectively of the insert and'extending'away from the connecting portion 26 on those side portionss In addition to the desirability of-"maintaining the position of the clip-type insert during the bra zingoperation, which function, in the present instance, is accomplished by the clip- -like formation and shaped "surfaces of the insert; it is also desirable that the brazing metal, such as brass or bronze, shall be held in position: for effecting strongly brazed joints when the parts are= heated; For this purpose, I "have provided" preformed channel-type brazing-metal parts 35 and136 made of :relatively thin sheet. stock ':and bent: to'-..-fit over.- the; opposed :lcurvedj surfacesrof. theeinsert sidecportions 24sandj25: Forrthezac-t Furthermore; for producing;=

commodation of the projecting lug portions 33 and 34 on the side portions 24 and 25, openings 31 and 38 respectively are provided in the brazing metal parts.

In the assembly of the elements prior to the application of heat for effecting the brazing, the channel-type brazing metal parts 35 and 36 are placed upon the opposite side portions 24 and 25 of the insert, as indicated in the exploded view- 'of2"Eig. 5. j The insert is their preferably pressedonto' theseat post masttube lfland then brought into embracing relationship with the upper reach tube I4, so that the side portions 24vand-r25zare effectively inserted between the adjoined seat post mast l0 and upper reach tube Wand the inner surfaces of the side tubes l8 andul 9; When. thus applied, the brazing material on the inner and outer surfaces of the insert sideportions is conformed to the adjacent tube and insert surfaces while being held in close contactrtherewithz. Thus,iwherrthe assembledtparts are; heatedlsufiiciently by, the high: frequency: induction; method .or T otherwise; rugged-l brazed; joints:hayingsubstantial surfaceareas .are.-:pro:-.-

duced;

Since parts; such: as .tubes and other;exteriorly contoured membersimay be produced with: con-1 sistency inaproduction, but are rather diflicu-ltrto' deform with-consistency; and withoutnconsider able expense, the use of mydisclosedmethod and; apparatus, including, the ,metal insert,- havewdefinite and material manufacturing, advantages: from the standpointsof both production'cost and consistency; Strongqand rugged joints are=:c0n'-. sistently produced: in :production by my disclosed method andapparatussince the inserts can bevery readily produced with consistency to fit the: partsawhich are rtOf; be joinedrand further, because -the present .material isrconsistently I held: in its proper. position andmay bewsubjected: touniform: heatingrtreatment. It is tobe under-- stood. in the :consideration of this invention that brazing and. welding: are. deemed to be. quite equivalent, and-thatvthe adaptation of mywmethodrz-and. apparatus; which include the use of a formed insert betweenltheparts to be'joined and conforming .to the, surface of r the. adjacent parts are v adaptable for either brazing or welding process, asthose. terms are used in their more. limited sense. 1

From the foregoing description and reference. to the accompanying drawingsit may be'readil-y; appreciatedvthat Lhave provided amethod and apparatus which, although illustratively dis.- closed in aparticular application, are applicable to many adaptations in which parts having-nor mallyrnoneconforming or non-euniformly; curved surfaces are to besecurely held together by brazing welding; or the: like. As has also been pointed. out, my; method: and: apparatus are adapted to the :provision of .jconsistent results in production: at reasonable cost.

While :I havezillustratedgaz preferred: em'bodi ment of; my; invention; many; modifications may; beemade-zwithout departingxfrom' the spiritxofi'the. invention, and I do not wish tobeliinitedztogthe precise :details: of :construction set forth; but-idesirentozavail myselfof all changes within the scope of. the appended: claims;

7 Having thus described my invention, whatrI claim-was new randsdesire ,to secure by Letters ."Patent iof the United rZStates; is:

l. Irrsan: elo'ngatedsand strengthened brazedjoint: connecting the: :sidezsurfaces of: atplurality. of non-complementarily sshapzed'emembersiinoludi-i 5 ing an intermediate member and spaced parallel and longitudinally extending side members on opposite sides of the intermediate member, the combination comprising a coined steel clip having side portions conforming to and embracing opposite side surfaces of the intermediate member, said side portions of the clip also having outer surfaces conforming to and engaging said spaced parallel and longitudinally extending side members, and brazing material securing each of said members to the conforming portions of the clip.

2. In a brazed joint for securing the side surfaces of two substantially coplanar and adjoining frame tubes to side tubes disposed in opposed relationship adjacent opposite sides of the frame tubes. the combination comprising a metal cliptype insert having side portions and a connecting portion integral with the side portions, said side portions each having opposed inner surfaces shaped to conform to side portions of the frame tubes and outer surfaces shaped to conform to portions of said side tubes, and brazed joints be- 63 tween each of said tubes and the conforming surfaces of said insert.

FRANK W. SC'HWINN.

5 REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 10 Number Name Date 474,584 Tobey May 10, 1892 679,082 Latta July 23, 1901 793,958 Richardson July 4, 1905 1,651,891 Hodges Dec. 6, 1927 15 1,823,028 Caldwell Sept. 15, 1931 2,117,107 Soderberg May 10, 1938 2,151,533 Schwinn Mar. 21, 1939 FOREIGN PATENTS 20 Number Country Date 536 Great Britain 1910 581,481 France Nov. 29, 1924 226,058 Switzerland Mar. 15, 1943 

